Machine for making screw-taps



PETERS. PHOTO-LITHOGRAPHER, WASHINGTON. D. C4

5 Sheets-Sheet 2. J J GRANT n Machine for Making Screw Tap-s. No.230,629.

Patented Aug. 3, 1880.

With aw es.

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N. PUDE. PWUTMOGRPMER. WASHINGTON' c' a'sheets-sh-eua. Jv. J. GRANT.

/Maohine fori-Making Screw Tap-s.

No. 230,629. Patented Aug.`3,1s8o. I

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5 sheets-sheet 4.' J J GRANT Mach-ine forMaki11g Screw Taps.. Y No.230,629.

Patented Aug.I 3,Y 1.8/80.

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N-PEIHS. PHOTLLUHQGRPNER. WASHINGTON. Dv

5 Sheets-Sheet;` 5.

Pat-e nt'ed Aug; 3,1880."

J.: J. GRANT. y y Machine for Making Screw Taps.

K n I UNTTED STATES PATENT OFFICE.

JOHN J. GRANT, OF HARTFORD, CONNECTICUT.

MACHINE FOR MAKING SCREW-TAPS.

SPECIFICATION forming part of Letters Patent No. 230,629, dated August3, 1880.

I Application filed May 18, 1878.

To all whom it may concern:

Beit known that I, JOHN J. GRANT, of Hartford, in the county of Hartfordand State of Connecticut, have invented certain new and usefulImprovements in Machines for Making Screw-Taps; and 1 do hereby declarethat the followingl is a full, clear, and exact description thereof,whereby a person skilled in the art can make and use the same, referencebeing had to the accom panying drawings, and to the letters of referencemarked thereon.

Like letters in the figures indicate the same parts.

My improvement relates to machines designed for cutting screw-threadsupon blanks, and especially for threading screw-taps.

My invention consists in the construction and arrangement of the severalparts of the machine, and in the combination and arrangement oftheseveral devices by which the proper motions are given to thecutting-tools, as will be hereinafter described.

' In the accomlntnying drawings, on ve sheets,

Figure lis a view ot' the machine from the front side. Fig. 2is a topview. Fig. 3 is an end view with the tail-block removed, so as to showthe sliding tool-carrier. Fig. 4:' is a view of the tool-carrier fromthe opposite side to that shown in Fig. 1. Fig. 5 is an enlarged view ofthe mechanism for shifting or reversing the motion ofthe machine. Fig. 6is a vertical section through the tool-carrier upon an enlarged scale.

My improved machine has the general form and construction of a lathe.

A is the bed or frame for sustaining the several parts of the machine. Bis the headblock.V C isthe sliding tail-block. D is the slidingtool-carrier. E is a horizontal shaft or spindle turning `in bearings inthe headblock, in the usual manner in lathes. G and H are loosepulleysupon the shaft E, between which is a sliding' clutch, J, which locksinto either pulley G or H to connect it with the shaft. The clutch J issplined to the shaft E and turns with it. The pulleys G and H receivetheir motion from belts connected with the main shaft, and are runcontinuously while the machine is in operation, turning in oppositedirections. K and L are geared wheels, which communicate motion from the'shaft E to the screw-shaft M. Upon this screw is 'a traveling nut, N,which operates the clutch J, as will be hereinafter described, and whichis conm ctedv by the rod O to the tool-carrier to give it itslongitudinal motion upon its guides or ways. P is a fork running in agroove in the clutch J, for operating it. This fork P is firmlyconnected to the shipping-rod R, which gives motion to it and operatesthe clutch.

The traveling nut N is provided with an arm or bracket, N', whichembraces the shipping-rod l?, and also the rod S, which serves to unlockthe dogs T and T at the ends of the shipping-rod.

U and U' are springs upon the shipping-rod for the purpose of throwing`it when pressed bythe bracket N. R' and S' are stops upon therods R andS, to adjust the time of operating the clutch to lany desired-amountotmotion of the bracket N.

1n Fig. 5 the position of the several parts is that when the clutch hasjust been thrown to the left. The bracket N then travels to the right,compresses the spring U', comes in contact with the stop S', Aand movesthe rod S so that its inclined end draws down and releases the dog T'.The pressure of the spring U then instantly shifts the clutch andreverses the motion ot' the machine. At the same time the dog T, at theother end ot the shipping-rod, locksintoits notch, being pressed upwardby a spring, as shown in the drawings.

When the clutch J is shifted, as above-described, the motion of theshaft E is reversed, which also reverses the motion of the screw M,thereby causing the nut N to move in the opposite direction, and with itthe tool-carrier D, to which it is connected by the rod O.

V and V are two movable tool-posts, which slide out and in upon thebed-plate W. This plate also slides laterally across the machine uponthe carrier D, which runs upon the Ways of the bed or frame A. X and Xare cuttingtools, of which two are used, one on each side of the work.One tool cuts when the carrier is moving in one direction, and the otherwhen the motion is reversed, and each tool cuts upon one side only, thisdoing much better work than when both sides of the tool are used. Y andY' are cylindrical tool-holders fitting into IOO sockets in thetool-posts V and V', so that they can be turned and adjusted upon theiraxes to set the tools atthe proper angle for cutting the thread.

The tool-holder Y', when placed in its proper position, is tirmlyclamped in the tool-post by means ofthe nut Z.

The tool-holder Y is made adjustable in a rotary direction upon its aXisby means of the tangentserews A2 A2 acting upon the arm B2. (J2 is ascrew for adjusting the tool to and from the work.

The top part of the tool-post V is made laterally adjustable by meansof' the screw D2, for giving the two tools their proper relativepositions. The two tool-posts move upon suitable slides to and from thework upon the pla-te W, and are furnished with nuts working upon rightand left screw-threads on the feedrod E2. This feed-rod is driven by aratchet, G2, and a double pawl, H2, the two arms ot which ditt'er inlength by halfa tooth, so as to give a tiner motion. These pawls aremoved by the arm J2, to which they are attach ed, passing over the camK2 upon the frame ot' the machine. Then not passing over K2 the end ofJ2 runs upon a horizontal slide.

The ratchet G2 is attached to the feed-rod by means of a frictionband,(shown at L2 in Fig. 6, so that when the tool-posts have approached eachother to the proper point and are stopped by the device that will behereinafter described the ratchet will slip on the rod and the feed willbe stopped.

M2 is a rod for adjusting the limit of approach of the tool-posts towardeach other. It passes through the post V' by means of a screw-thread,and enters into a hole, in which it fits so as to exclude oilor chips,in the post V. When it touches the bottom ot' this hole the tool-postscannot approach each other any farther. This adjustment exactly detcrmines the depth to which the tool cuts, and makes the work done of an exactgage.

The plate W slides upon the carrier D, and is moved back and forth acertain distance at each reverse movement ofthe carrier, so as to bringthe two tools successively into position as the carrier moves inopposite directions. This throw is given to the plate XV by means ofthepin P2, which fits in a cam-slot in the slidingl plate N2. (Shown atO2in Fig. 2.) The plate N2 is moved at the end ot' each movement ot' thecarrier D by striking against the adjustable screws R2 and S2, attachedto the frame of the machine. This movement of the sliding plate W alwaysbrings the tools tothe same position plus the amount ot' feed given bythe feed-screw E2.

What I claim as my invention is- 4 1. The combination of theshipping-rod R, the springs U U', the dogs T T', and the slidingunlocking-rod S, the said rods being furnished with stops R and S', asan automatic device for instantly moving the clutch Jat the end of thethrow of the nut N, substantially as herein described.

2. The combination ofthe f'rictional ratchetwheel G2, the feed-rod E2,and the stopping device M2 with the tool posts V and V', substantiallyas herein described.

3. The screws A2 and arm B2, in combiua- Y tion with ahorizontally-rotating cylindrical tool-holder, Y, substantially asherein described.

JOHN J. GRANT.

Witnesses W. H. BINNs, WALTER L. CHENEY.

